SugaR 190317 64 POPCNT topped the table here with the best solving performance of 91/111 positions.

Under these conditions it was highlighted giving all engines the same hash value does not necessarily maintain an optimised approach suggesting some engines are much more hash sensitive than others.

Stockfish 8 impressed with its 16 core scoring consistency solving the same number of positions irrespective of the hash setting but with a clear impact on time to solve. I may be wrong but I assumed SugaR being a Stockfish derivative would have similar characteristics but I ran out of time to continue running the tests to prove the theory.

Houdini 5.01 gave best performance with 4 Gb hash that is the same value I obtained for Houdini 4 in game play when I experimented with different hash levels some time ago.

There was also the curious result where Komodo 10.3 scored 2 more positions on my slower old quad machine with 1 Gb hash than it did with 16 cores and 4 Gb hash on the dual Xeon machine.

I have attached the Chessbase files and a pgn database of all of the results when there are some extra engine/hash combinations included.

Hi, although the title I had sent to me was Eigenmann Test Your Knowledge, the position identifier indicates the positions were from the Eigenmann Rapid Engine Test position test suite. However there are indicated themes for the positions. I thought I had attached it in the zip file attachment just above the results list.

It is worth checking against the continuations given by Eigenmann that can be seen in the .pgn contained in the zip file of my original post. For example, I clipped analysis from Stockfish 8 that solved ERET 015 eventually indicating +24.25 at 66 ply depth.

I did intend rerunning the engines with 16 cores and 8Gb hash with 10 minutes per position but matches demand took over priorities. Arasan 20 test suite probably next in a few days time when current engine matches completed.

For the first position, engines' first choice seems to be Rf2 that as you say is also winning but when shown Na8, Stockfish 8 scores it ..Nxc2 00.00 within a typical tournament time for a move but Komodo 10.4 quickly sees it is winning for White.

I wonder how many test set positions now have two or more solutions when previously it was thought there was just one definitive move?

I just gave an hour or so to asmFishW_2017-05-02_popcnt with this. It would naturally have chosen 1.Rf2 and its score after an hour confirms it is winning for white. Having cleared the hash and briefly shown it 1.Na8 the ensuing analysis suggests it finds a mating position but out of bounds in terms of distance to mate.

As for ERET 025, whereas the asmFishW_2017-05-02_popcnt engine finds and sticks with1.Bf4, after an hour it is scoring it no better than equal at 75 ply depth. However, once shown 1.Bxd8 it very quickly gives an increasing score when there is no doubt about the outcome.

As with ERET 037, the engine gives an indication of mate in ERET 025 with 58.Bxd8 but here showing a specific depth scoring it #64.

Houdini 5.01 Pro x64-popc finds 58.Bxd8 winning in just 12 seconds at 35 ply depth but after 2 hours 20 minutes does not have the search depth to see the deep mate showing +19.80 46/81.

I have Komodo 10.4 changing from 58.Bc1 0.36 54 to 58.Bxd8 0.48 54 after 11 minutes and now 58.Bxd8 5.61 54 at 20 minutes.

Little doubt then Bxd8 is a win but Bf4 ... nothing more than a draw here with the top 3 engines.

What were the scores for the Bg7 choices?Matefinder's score for the alternative move Bxc4+ was better than the best score SF found for Bg7 in my tests.Does not mean that matefinder is right. But it still casts doubt on the solution for me.

Just finished running Deep Fritz 10.1 through the test set on one of my overclocked quads. It came out bottom of the list scoring just 42/111 for 37.8%. I suspect engines of a similar era would score similarly. It is likely to score better where pure tactics are involved but still falls short of today's engines.

Feel free to test my theory yourself. It is not a theory for me but a statement of fact based on my findings with other test suits. Publish your result findings of Deep Fritz 10.1 against today's modern engines and let us see if it differs much from mine!

Deep Fritz 10.1 fairs better in the tactically oriented Arasan 18 positions but is still no match for today's engines. The 4 and 16 cores performances highlights the engine is not particularly good by today's standards.

> How long did were the engines allowed to ponder for each position in the Arasan test you referenced here?

The recommended 30s. That is clear in the test set pgn of my original post. Given the improvement from 4 to 16 cores, extending the time to say 4 minutes and giving 4 Gb hash may bring 4 core testing closer to the 16 core results.

I completed runnng the early "old school" engines through the Eigenmann Knowledge test ...

Thanks. Finally we can put to rest the myth that Shredder was the top endgame engine back in the day... DF10 understands blockades, king and pawn endgames, etc MUCH better than any engine of the same era.

I do question your statement that Eigenmann test is knowledge based however. I don't think any modern programmer has the chess elo to add any new cutting-edge endgame knowledge. I would be very surprised if Stockfish 8 or Houdini 5 has endgame knowledge not present in Deep Fritz 10.1

> DF10 understands blockades, king and pawn endgames, etc MUCH better than any engine of the same era.

I am not sure that is true. Deep Shredder 10.1 is the only engine I have that scores some blockade positions at zero or close to zero when there is a large material disadvantage. I cannot recall seeing a zero or close to zero score with Deep Fritz 10.1.

Deep Shredder 10.1 has its own playing style and was slightly stronger than Deep Fritz 10.1. Checkout the CEGT 40/20 Elo ratings ...

You are comparing DF 10 on one core with Deep Shredder 10 on 4 cores. Version 10 only used one core at 4 CPU, it was a bugg. Deep Fritz 10.1 is with correctly functioning multiprocessing and has a higher elo than Deep Shredder 10 at all time controls. It does not have any changes to its game playing algorithms.